Earth's Troposphere Is Expanding due to Climate Change
3 Min Read
Planes may have to fly higher to avoid turbulence.
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Troposphere; the lowest densest part of the earth's atmosphere
Climate change is causing the Earth's atmosphere to rise, a new study shows.
Weather balloon measurements, taken in the Northern Hemisphere over the past 40 years, have revealed that the troposphere, the lowest layer of Earth's atmosphere, has been expanding upward at a rate of roughly 164 feet (50 meters) per decade. And according to published Nov. 5 in the journal Science Advances, climate change is the cause.
"This is an unambiguous sign of changing atmospheric structure," study co-author Bill Randel, a scientist at the National Center for Atmospheric Research in Boulder, Colorado, said in a statement.
"These results provide independent confirmation, in addition to all the other evidence of climate change, that greenhouse gases are altering our atmosphere."
The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere, and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.
The troposphere is the layer of the atmosphere we live and breathe in. It extends from sea level to a height ranging from 7 km above the poles to 20 km over the tropics.
When it's hot, the air in the atmosphere expands, and it contracts when it's cold, so the troposphere's upper boundary, called the tropopause, naturally shrinks and expands with the changing of the seasons.
But by analyzing atmospheric data such as pressure, temperature, and humidity and pairing it with GPS data, researchers showed that due to increasing quantities of greenhouse gases trapping more heat in the atmosphere, the tropopause is rising higher than ever before.
It is worth noting that the rate of the rise seems to be increasing, and researchers estimated that human activity accounted for 80% of the total increase in atmospheric height.
Climate change isn't the only human-made driver of the rising tropopause. The stratosphere is shrinking too, thanks to the past release of ozone-depleting gases.
Scientists are still not sure how a rising tropopause will influence the climate or weather, although it could force planes to fly higher in the atmosphere to avoid turbulence.
"The study captures two important ways that humans are changing the atmosphere," Randel said.
"The height of the tropopause is being increasingly affected by emissions of greenhouse gases even as society has successfully stabilized conditions in the stratosphere by restricting ozone-destroying chemicals."
